This invention relates to a chain link for use in making jewelry chains, and more specifically, a chain link having an eccentric or offset gap.
Conventional rope chain is formed by intertwining jewelry links 10 of the type illustrated in FIG. 2, which is used in the formation of rope chains, said link 10 having an outer periphery 12, an inner periphery 14, a gap 16 and a thickness 18. Link 10 may be formed from a solid or hollow wire 5 as is known in the art shown in FIG. 1, or may be formed by stamping or punching as is also known in the art. Other methods of link formation are known.
The link 10 of FIG. 2 used in the assembly of rope chains has certain conventional characteristics. First, the inner and outer peripheries 12 and 14 respectively usually have the same or similar shape, and in this case an annular configuration. The thickness 18 is also generally consistent throughout the link 10. In addition, the gap 16 falls on a centerline plane 30 that cuts the link 10 in half, such that a distance to a first outermost point 32 defined along a first plane 31 extending perpendicular to the centerline plane 30 is the same as a distance to a second outermost point 34 defined along a second plane 33 extending perpendicular to the centerline plane 30.
In other words, in a conventional link 10 having an annular configuration as shown in FIG. 2, the centerline plane 30 and the outermost dimensions 32, 34 will each fall on a diameter 35 of the link 10, such that the addition of the outermost dimensions 32, 34 from the centerline plane 30 will equal such diameter 35. The intertwining of such chain links 10 results in a chain 40 as illustrated in FIGS. 3 and 4, wherein the overall thickness of the chain 40 is substantially equal to the same diameter 35 of the chain link 10, or to the distance between the outermost dimensions 32, 34 (FIG. 2). Thus, the thickness 35 of the chain of FIG. 3 is directly related to the distance between the outermost dimensions 32, 34 of link 10 or the distance of each outermost dimension 32, 34 relative to the centerline plane 30.
The intertwining of chain links 10 as shown in FIG. 4 forms a double helical chain configuration as shown in FIG. 3. Thus, the chain appears to have two separate xe2x80x9chelixesxe2x80x9d of links, one helix designated in FIG. 3 by a small xe2x80x9c∘xe2x80x9d and the other designated by a small xe2x80x9cxxe2x80x9d. In conventional rope chain construction, each helix of material represents one side of an intertwined link. For instance, the xe2x80x9c∘xe2x80x9d helix in FIG. 3 might represent the end 32 of link 10 illustrated in FIG. 2, while the xe2x80x9cxxe2x80x9d helix might represent the end 34 of link 10 illustrated in FIG. 2. As shown in FIG. 3, the xe2x80x9c∘xe2x80x9d and xe2x80x9cxxe2x80x9d helixes appear to be dimensionally identical, which is due to the uniform distance between the center plane 30 and each outer edge 32, 34. This is also illustrated in FIG. 4, wherein a cross-section through a chain section has a uniform, circular diameter 35.
A conventional oblong link 50 as disclosed in U.S. Pat. No. 4,996,835 and illustrated herein in FIG. 5, having an inner periphery 52, outer periphery 54, thickness 56 and gap 58, when intertwined to form a chain illustrated in FIG. 6, will produce a chain thickness 65 equal to the distance between the outermost points 62, 64, which lie along planes 61, 63 relative to the centerline plane 60. The centerline plane 60 or gap plane 60 is generally defined through the gap 58 along a vertical axis that extends perpendicular to the major axis of the link and parallel to the minor axis of the link. As illustrated in FIG. 9, a jewelry rope chain is formed by successively intertwining chain links 50a-50f as is known in the art (i.e., in an alternating relation or by other methods known in the art, one such method being shown in U.S. Pat. No. 4,934,135 to Rozenwasser), the thickness 65 of the chain being determined by adding the distances of the outermost points 62a, 64a (see link 50a in FIG. 9 for example) relative to the gap plane 60. More particularly, it will be understood with reference to the discussion of the link of one embodiment of the present invention that the chain thickness 65 can be defined as the distance between outermost points of two successively intertwined chain links. In the case of the link 50 of FIG. 5, because the outermost points 62, 64 are at the same distance from the centerline plane 60, the chain width and the link width are the same.
However, the present inventors have discovered that by using a link wherein the distance between each outermost point relative to the centerline (gap) plane is not the same, a chain can be produced with a greater chain thickness than link width, but without using a greater amount of material in each link or chain. In other words, by eccentrically positioning the gap so that it does not fall along a plane that splits the link in half, a resultant chain width becomes greater than, and not substantially equal to, the major diameter of the link.
A jewelry chain link suitable for intertwining with other jewelry chain links to form a jewelry chain comprises an inner periphery, an outer periphery, a thickness defined between the inner and outer peripheries and a gap extending between the inner and outer peripheries for intertwining one jewelry chain link with another. First and second outermost edge dimensions along the outer periphery are defined relative to a plane extending through the gap, such that the distance from the plane to each of the first and second outermost edges is different.